MCB4150 Exam 3 Study Set With
Complete Solution
Superphylum of: Chlamydiae, Planctomycetes, and Verrumicrobia - ANSWER -inhabit
soils, aquatic systems, and in association with eukaryotic hosts
-superphylum LACKS peptidoglycan
-UNIQUE because cells have internal compartmentalization
Planctomycete - ANSWER -free-living aquatic oligotrophs
-divide by budding
-Components= flagellum, stalk, and pilus
Stalk: attachment
Flagellum: movement
Pilus: budding
-S-layer Cell Wall; resistant to antibiotics that disrupt peptidoglycan synthesis
~GENES for peptidoglycan synthesis still found, may be purposed in different ways from
other bacteria
-some are nucleated: Nucleoid is surrounded by nuclear envelope
-> DNA covalently closed, circular, and supercoiled
-> nuclear membrane is invagination in cytoplasmic membrane
-some members are nitrifying bacteria that oxidize ammonia
Anammox - ANSWER -anoxic ammonia oxidation
(classic nitrifying bacteria are aerobes, but ammonia can also be oxidized under anoxic
conditions)
-oxidation of ammonia with Nitrite/NO2- as external electron acceptor to yield gaseous
nitrogen
Anammox Reaction - ANSWER NH4+ + NO2- -> N2 + 2H2O
Delta G= -357 kJ
-Nitrite reduced to nitric oxide by Nitrite Reductase, then Hydrazine Synthase mediates
nitric oxide reacting with ammonia to produce hydrazine (very strong reductant), then
, Hydrazine Dehydrogenase oxidizes hydrazine to form N2 gas
-electrons generated funneled into ETC where they form a PMF, and electrons also
donated to initial reductive steps
-ATPase is in the membrane of anammoxosome for ATP generation
Enzymes:
~Nitrite Reductase
~Hydrazine Synthase
~Hydrazine Dehydrogenase
REDOX Reaction:
~Ammonia= e- donor
~Nitrite= e- acceptor
~Hydrazine= strong reductant
Brocadia anammoxidans - ANSWER -member of Planctomycetes
-autotroph
-catalyzes anammox
-fixes CO2 via Acetyl-CoA Pathway
Anammoxosome - ANSWER -unit membrane structure where anammox reaction occurs
-protects the cell from toxic intermediates produced during anammox reaction
-made of DISTINT lipids: Ladderane Lipids, forming dense membrane structure
preventing diffusion of substance from anammoxosome to cytoplasm
-> ester AND ether bonds
Chlamydiae - ANSWER -obligately intracellular parasites
-simplest biochemical capabilities of ALL known bacteria
-thought to be "energy parasites", but have genes for ATP synthesis, peptidoglycan
biosynthesis, and some "eukaryotic-like" genes
~"eukaryotic-like" means they were horizontally inherited from the host
-gram negative cell wall, LACK peptidoglycan
~lack sensitivity to penicillin
Complete Solution
Superphylum of: Chlamydiae, Planctomycetes, and Verrumicrobia - ANSWER -inhabit
soils, aquatic systems, and in association with eukaryotic hosts
-superphylum LACKS peptidoglycan
-UNIQUE because cells have internal compartmentalization
Planctomycete - ANSWER -free-living aquatic oligotrophs
-divide by budding
-Components= flagellum, stalk, and pilus
Stalk: attachment
Flagellum: movement
Pilus: budding
-S-layer Cell Wall; resistant to antibiotics that disrupt peptidoglycan synthesis
~GENES for peptidoglycan synthesis still found, may be purposed in different ways from
other bacteria
-some are nucleated: Nucleoid is surrounded by nuclear envelope
-> DNA covalently closed, circular, and supercoiled
-> nuclear membrane is invagination in cytoplasmic membrane
-some members are nitrifying bacteria that oxidize ammonia
Anammox - ANSWER -anoxic ammonia oxidation
(classic nitrifying bacteria are aerobes, but ammonia can also be oxidized under anoxic
conditions)
-oxidation of ammonia with Nitrite/NO2- as external electron acceptor to yield gaseous
nitrogen
Anammox Reaction - ANSWER NH4+ + NO2- -> N2 + 2H2O
Delta G= -357 kJ
-Nitrite reduced to nitric oxide by Nitrite Reductase, then Hydrazine Synthase mediates
nitric oxide reacting with ammonia to produce hydrazine (very strong reductant), then
, Hydrazine Dehydrogenase oxidizes hydrazine to form N2 gas
-electrons generated funneled into ETC where they form a PMF, and electrons also
donated to initial reductive steps
-ATPase is in the membrane of anammoxosome for ATP generation
Enzymes:
~Nitrite Reductase
~Hydrazine Synthase
~Hydrazine Dehydrogenase
REDOX Reaction:
~Ammonia= e- donor
~Nitrite= e- acceptor
~Hydrazine= strong reductant
Brocadia anammoxidans - ANSWER -member of Planctomycetes
-autotroph
-catalyzes anammox
-fixes CO2 via Acetyl-CoA Pathway
Anammoxosome - ANSWER -unit membrane structure where anammox reaction occurs
-protects the cell from toxic intermediates produced during anammox reaction
-made of DISTINT lipids: Ladderane Lipids, forming dense membrane structure
preventing diffusion of substance from anammoxosome to cytoplasm
-> ester AND ether bonds
Chlamydiae - ANSWER -obligately intracellular parasites
-simplest biochemical capabilities of ALL known bacteria
-thought to be "energy parasites", but have genes for ATP synthesis, peptidoglycan
biosynthesis, and some "eukaryotic-like" genes
~"eukaryotic-like" means they were horizontally inherited from the host
-gram negative cell wall, LACK peptidoglycan
~lack sensitivity to penicillin
